1. Field of the Invention
The invention relates to an electromotive adjustment drive for an adjustment element in a motor vehicle. An adjustment drive in this context can be understood to be, for example, a sunroof drive, a door drive, a rear door drive, a seat adjustment drive or a window lifter drive.
2. Description of the Background Art
A electromotive adjustment drive usually includes a drive module, which, in turn, may be composed of a motor module and a gear module, as well as an electronic module. The drive module includes an electric motor whose armature (rotor), which is mounted on a motor shaft, is rotationally supported in a pole pot in which permanent magnets are held in a bipole or multipole arrangement. The motor shaft protruding from the pole pot is guided into a gear housing having a worm gear, for example via a brush holder. An electronic module having a printed circuit board may be positioned on the gear housing in the manner of an interface. In this case, a mechanical connection is usually established between the electronic module and the gear housing, and the printed circuit board is also usually electrically contacted with motor contacts, which, in turn, are connected to carbon brushes of the electric motor, which is conventionally designed as a commutator motor.
For example, an electromotive window lifter drive, which has a modular design of the type described above, is known from DE 101 08 414 B4. The drive module, which includes the motor module and the gear module, is always the same, while the electronic module has different designs and which, in its diversity, may be provided with a modular configuration. The interface to the drive module is always the same, while the electronic module may be designed as a simple plug-in contact (power on/off) or as comparatively complex electronics. A distinction may also be made between positioning in a wet area and a dry area.
Due to the increasing number of electronic components for implementing different functions, the electromagnetic compatibility requirements are also higher. Interference must be avoided as reliably as possible, but at least dampened as effectively as possible. Any additional components needed for this purpose, for example coils (chokes) or capacitors, require additional installation space. In addition, it is desirable to integrate sensor electronics in the form of Hall sensors and a corresponding evaluation unit into the electronics or the electronic module.
To accommodate interference suppression electronics of this type in as little space as possible, it is known from DE 103 18 734 A1 to provide a separate printed circuit board which is inserted into the brush holder and is contacted via spring contacts.
A special clamping contact is furthermore known from DE 10 2005 055 740 A1, in which an electrical conductor, which, in turn, is designed as a spring contact, rests against a contact surface (contact pad) of the printed circuit board and is clamp-contacted with the pole pot for connecting to ground. The printed circuit board itself is, in turn, inserted into the gear or brush holder housing in a retaining groove provided in the housing base. The printed circuit board is held on a connector of the slide-in module.